2ND CRITICAL-POINT AND LOW-TEMPERATURE ANOMALIES IN THE PHYSICAL-PROPERTIES OF WATER

A metastable P-T phase diagram is calculated for water on the basis of a two-level model. The line of transitions between low-density amorph ous ice and high-density amorphous ice terminates at a critical point with the coordinates T-c=225 K, P-c=0.33 kbar. The proximity of this c ritical point to atmospheric pressure is responsible for the low-tempe rature anomalous behavior seen in the physical properties of water at standard pressure. The temperature dependence of the specific volume a nd that of the specific heat calculated in this model agree well with experimental data. (C) 1994 American Institute of Physics.